Along with the rapid market expansion of notebook personal computers, cell phones, electric cars and the like, high-energy density secondary batteries are in demand. Means of obtaining high-energy density secondary batteries include a method of using a large-capacity negative electrode material, and a method of using a nonaqueous electrolyte liquid excellent in stability.
Patent Literature 1 discloses the utilization of an oxide of silicon or a silicate salt for a negative electrode active substance of a secondary battery. Patent Literature 2 discloses a negative electrode for a secondary battery having an active substance layer containing a carbon material particle capable of occluding and releasing lithium ions, a metal particle capable of being alloyed with lithium, and an oxide particle capable of occluding and releasing lithium ions. Patent Literature 3 discloses a negative electrode material for a secondary battery, which is obtained by coating carbon on the surface of a particle having a structure in which microcrystals of silicon are dispersed in a silicon compound.
Patent Literature 4 discloses the use of a negative electrode capable of occluding and releasing lithium, and the use of a nitrile compound having a carbon-carbon unsaturated bond as an electrolyte liquid.
Patent Literature 5 discloses the use of an electrolyte liquid containing a nitrile compound having a specific structure.